ULTRACAPACITOR ELECTRODE WITH CONTROLLED SULFUR CONTENT

• US 20080201925A1
• Filed: 02/28/2007
• Published: 08/28/2008
• Est. Priority Date: 02/28/2007
• Status: Abandoned Application

• Current Assignee: Tesla Inc.
• Original Assignee: Maxwell Technologies Incorporated (Tesla Inc.)
• Inventors: Mitchell, Porter, Xi, Xiaomei, Zhong, Linda
• Application Number:
  US11/680,516
• Publication Number:
  US 20080201925A1
• Time in Patent Office: Days
• US Class Current: 29/25.03
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

Particles of active electrode material are made by blending mixing a mixture of activated carbon and binder. In selected implementations, sulfur level in the activated carbon is relatively low and the binder is inert. For example, sulfur content of the activated carbon and the resultant mixture is below 300 ppm and in other implementations, below 50 ppm. The electrode material may be attached to a current collector to obtain an electrode for use in various electrical devices, including a double layer capacitor. The electrode decreases current leakage of the capacitor.

Claims

1. A method of making an active electrode material, the method comprising:

providing activated carbon with a sulfur content not exceeding about 50 parts per million;

providing binder; and

,

mixing the activated carbon and the binder to obtain a mixture of active electrode material.

4. A method in accordance with claim 1, wherein the operation of providing the activated carbon includes providing activated carbon in amount of between about 80 and about 97 percent by weight, and wherein the operation of providing the binder includes providing binder in amount of between about 3 and about 20 percent by weight.

5. A method in accordance with claim 1 further comprising providing an additional additive component having a sulfur content not exceeding an amount whereby the mixture of active electrode material has a sulfur content not exceeding about 50 parts per million.

6. A method in accordance with claim 5, wherein the additional additive component is conductive carbon.

7. A method in accordance with claim 1, wherein the binder includes PTFE.

8. A method in accordance with claim 1, wherein the operation of mixing is performed without processing additives.

9. A method in accordance with claim 1, wherein the operation of mixing includes dry blending the activated carbon and the binder.

2. (canceled)

3. (canceled)

10. An electrode comprising:

a current collector; and

a film of active electrode material attached to the current collector, wherein the activated carbon in the active electrode material has a sulfur content of about 0 to about 50 ppm.

12. The electrode of claim 10, wherein the active electrode material includes activated carbon and a binder, wherein the activated carbon is in an amount of between about 80 and about 97 percent by weight, and wherein the binder is in an amount of between about 3 and about 20 percent by weight.

13. The electrode of claim 10, wherein the active electrode material includes conductive carbon particles.

11. (canceled)

14. A method of making an active electrode material, the method comprising:

providing activated carbon with a sulfur content not exceeding about 50 parts per million;

providing low contamination level conductive carbon particles;

providing binder; and

mixing the activated carbon, the conductive carbon, and the binder to obtain a mixture.

17. A method in accordance with claim 14, wherein the providing conductive carbon operation further comprises providing conductive carbon with a sulfur content not exceeding about 50 parts per million.

15. (canceled)

16. (canceled)

18. (canceled)

19. An electrochemical double layer capacitor comprising:

a first electrode comprising a first current collector and a first film of active electrode material, the first film comprising a first surface and a second surface;

the first current collector being attached to the first surface of the first film;

a second electrode comprising a second current collector and a second film of active electrode material, the second film comprising a third surface and a fourth surface, the second current collector being attached to the third surface of the second film;

a porous separator disposed between the second surface of the first film and the fourth surface of the second film;

a container;

an electrolyte;

wherein;

the first electrode, the second electrode, the porous separator, and the electrolyte are disposed in the container;

the first film is at least partially immersed in the electrolyte;

the second film is at least partially immersed in the electrolyte;

the porous separator is at least partially immersed in the electrolyte;

each of the first and second films include a mixture of carbon with a sulfur content not exceeding about 50 parts per million and binder.

20. (canceled)